Not to speak for Gryphon (I too look forward to reading his opinion on this) but here's my .02
$600 opens the door up to a lot of real good guns. You're still a little short for the custom 1911 market, but there are many real good handguns in that price range.
I guess there are a few things you need to think about.
1. Will this be a carry weapon. If it will you may want to look at compacts. But if not, then a full frame handgun would be a good choice.
2. How big are your hands. One of the problems with compacts is that some people with large hands have problems with compacts. Comfort is the
most important thing about a handgun.
3. Are you recoil sensative. Some people have a problem with recoil, if you fall into that category I'd stay away from .45acp.
If you've never fired a handgun, go to a local shooting range. They usualy have several models that you can rent and pump a few rounds though, and since many of them are also gun dealers, they may let you demo a gun or two (but you usualy have to demonstrate that you're real serious about purchasing for that).
As for brands, Glock, Sig, Kahr, and many other fine brands make good weapons in your price range. There are some advantages and disadvantages to each, but ultimatly you have to wrap your fingers around one (and preferably fire it) before you know if it's the right one for you. Again, comfort is what's important.
You may also look at a used handgun. There are real good deals to be found on used hardware that may not have had much use. Even without knowing a lot about guns, they are simple machines and most flaws are easily seen, even by the novice. However any reputible gun dealer should have no problem with you taking the gun to a gunsmith for inspection (this might have to be done douring a 10 day after purchase grace period or something like that).
For self defense I'd recommend one of the following calibers (generaly from least powerful to most).
9mm, .357sig, .40S&W, and .45acp (keep in mind that there is much disagreement in the gun community as to which of these is "best").
For myself I prefer .45acp (I kinda like recoil
) but have yet to fire a .357sig or a .40s&w so I can't comment on them, but I've read many good things about them (and may consider purchasing one of them instead of .45, but I wanna fire them first)
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